The Zak occurrence is located on a logging road, approximately 2.6 kilometres northwest of Targe Lake.
The oldest rocks exposed in the area are dull green intermediate volcanics of the Middle Jurassic Hazelton Group. They occur along the north-facing slopes and low-lying areas in the northern part of the area. Lithologies include reworked andesitic crystal tuffs and plagioclase-phyric flows. These rocks have been thermally metamorphosed to a fine-grained mottled pale pink and green rock with relict plagioclase phenocrysts where they are intruded by a biotite quartz monzonite plug. The intrusion is salmon coloured, medium grained and contains from 3 to 4 per cent weakly chloritized biotite. It may be correlative with the Jura-Cretaceous Francois Lake suite of intrusions that crops out predominantly to the north of the area. Grey chert pebble conglomerates (Cretaceous Skeena Group equivalents?) overlie Jurassic Hazelton Group rocks. Locally they are weakly silicified and are cut by veinlets of quartz-pyrite. The conglomerates are in turn overlain by pale grey-green hornblende phyric dacite to andesite flows that may be correlative with the Cretaceous Kasalka Group.
Maroon to cream-coloured, hematite-stained and variably argillically altered plagioclase phyric andesite to dacite flows, flow-banded rhyolites, rhyolite breccias, and associated felsic to intermediate lapilli and crystal tuffs, unconformably overlie all older rock units. These rocks are considered to be part of the Ootsa Lake Group. The flow-banded rhyolite forms a ridge that trends north westerly across the area. This unit appears to be part intrusive and part extrusive; it cuts all older stratified rocks in the area and in part overlies the argillically altered andesite flows. It is interpreted to be part of a flow dome complex.
Locally, quartz-calcite veins or fractures, up to 10 centimetres wide, cut Ootsa Lake Formation megacrystic porphyry. A sample of vein material assayed 0.223 per cent copper and 13.4 grams per tonne gold (Assessment Report 33670).
In 1988 and 1989, Noranda completed programs of geological mapping and rock, soil and silt sampling, seventeen trenches and a ground magnetometer survey on the area as the HC claims. During 1995 through 1997, Phelps Dodge completed programs of geological mapping and rock and soil sampling. In 2000 and 2001, the area was prospected by G.N. Goodall. During 2007 through 2012, Strategic Metals completed programs of geological mapping, rock, till and soil sampling, an airborne electromagnetic and magnetic survey and forty-one percussion drill holes, totalling 944.9 metres, on the area as the Zakco claims.
